UMLS:C0021051 - FACTA Search

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Query: UMLS:C0021051 (immunodeficiency)
71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

HIV-infected monocytes form highly invasive network on basement membrane matrix and secrete high levels of 92-kd metalloproteinase (MMP-9), an enzyme that degrades basement membrane proteins. In the present study, using matrigel as a model basement membrane system, we demonstrate that treatment of human immunodeficiency virus (HIV)-infected monocytes with interferon-gamma at 50 U/ml inhibited the ability of infected monocytes to form an invasive network on matrigel and their invasion through the matrigel matrix. These effects were associated with a significant reduction in the levels of MMP-9 produced by HIV-infected monocytes treated with interferon-gamma 1 day prior to infection with HIV as compared with that of untreated HIV-infected monocytes. Monocytes treated with interferon-gamma 1 day after HIV infection showed the presence of integrated HIV sequences; however, the levels of MMP-9 were substantially lower than those produced by monocytes inoculated with live HIV, heat-inactivated HIV, or even the control uninfected monocytes. Exposure of monocytes to heat-inactivated HIV did not result in increased invasiveness or high MMP-9 production, suggesting that regulation of metalloproteinase by monocytes was independent of CD4-gp120 interactions and required active virus infection. Furthermore, addition of interferon-gamma to monocytes on day 10 after infection inhibited MMP-9 production by more than threefold with no significant reduction of virus replication. These results indicate that the mechanism of interferon-gamma-induced down-regulation of MMP-9 levels and reduced monocyte invasiveness may be mediated by a mechanism independent of antiviral activity of IFN-gamma in monocytes. Down-regulation of MMP-9 in HIV-infected monocytes by interferon-gamma may play an important role in the control of HIV pathogenesis.
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PMID:Interferon-gamma inhibits HIV-induced invasiveness of monocytes. 749 70

Human immunodeficiency virus (HIV) infection has been associated with periodontal diseases in HIV-seropositive patients. In periodontal diseases, matrix metalloproteinases (MMPs) may play key roles in the extracellular matrix, basement membrane, serpin degradation, and modification of cytokine action. We characterized the 72 kDa type IV collagenase (gelatinase A, MMP-2) and 92 kDa type IV collagenase (gelatinase B, MMP-9) in the saliva of HIV-seropositive patients and seronegative healthy controls by activity measurements and quantitative immunoblotting. Immunoblot analysis with specific antibodies against MMP-2 and MMP-9 and their tissue inhibitors (TIMP-1, TIMP-2) disclosed that, independent of the phase of the patients' HIV infection, their salivary samples contained higher amounts of MMP-2 and MMP-9 immunoreactivities in pro- and active forms and the TIMP-1 and TIMP-2 inhibitors than did the control samples. Healthy control saliva contained only slight immunoreactivities for gelatinases and TIMPs. However, as judged by the studied clinical and microbiologic indicators, HIV-seropositive patients showed only a slight tendency to develop periodontitis. Overall, an increased amount of gelatinases in saliva may reflect increased host response and defense activities in HIV infection.
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PMID:72-kDa and 92-kDa gelatinases in saliva of patients with human immunodeficiency virus infection. 968 21

To determine whether matrix metalloproteinase (MMP)-9 is a potential mediator involved in the frequently detected blood-brain barrier leakage in human immunodeficiency virus (HIV)-infected patients, zymography was used to detect MMP-9 activity in cerebrospinal fluid (CSF) samples of 80 HIV-infected patients and of 10 control patients. CSF MMP-9 activity was detected in 40% of HIV-infected patients (but not in controls) and was significantly more frequent in HIV-infected patients than in those without neurologic deficits (50% vs. 13.6%). The frequency of CSF MMP-9 activity did not significantly differ between neurologically symptomatic HIV-infected patients with or without opportunistic central nervous system disease (51.6% vs. 48.1%). Additionally, the presence of CSF MMP-9 activity in HIV-infected patients was associated with an increased CSF white blood cell count and an elevated CSF-to-serum albumin ratio, suggesting that it may play a role in blood-brain/CSF barrier leakage in HIV-infected patients.
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PMID:Presence of matrix metalloproteinase-9 activity in the cerebrospinal fluid of human immunodeficiency virus-infected patients. 972 58

The role of Mycobacterium avium isolates in modulating human immunodeficiency virus type 1 (HIV-1) replication was examined by use of an in vitro, resting T cell system. Two human clinical isolates (serotypes 1 and 4) but not an environmental M. avium isolate (serotype 2) enhanced HIV-1 replication. The M. avium-induced HIV-1 replication was not associated with cell activation or differential cytokine production or utilization. Addition of matrix metalloproteinase (MMP) inhibitors and their in vivo regulators, tissue inhibitors of metalloproteinases-1 and -2, abrogated M. avium-induced HIV-1 replication 80%-95%. The MMP inhibitors did not have any effect on the HIV-1 protease activity, suggesting that they may affect cellular processes. Furthermore, MMP-9 protein was differentially expressed after infection with clinical M. avium isolates and paralleled HIV-1 p24 production. Collectively, these data suggest that M. avium-induced HIV-1 replication is mediated, in part, through the induction of MMP-9.
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PMID:Involvement of matrix metalloproteinases in human immunodeficiency virus type 1-induced replication by clinical Mycobacterium avium isolates. 1047 41

Pathological evidence suggests that alterations of the blood-brain barrier (BBB) may occur in association with human immunodeficiency virus (HIV) dementia (HIVD). Increased BBB permeability could contribute to the development of dementia by facilitating the entry of activated and infected monocytes, as well as potentially toxic serum proteins, into the central nervous system. One mechanism by which BBB permeability may be altered is through increased activity of select matrix metalloproteinases (MMPs). In the present study, we examined the possibility that MMPs that target critical BBB proteins, including laminin, entactin, and collagen type IV, are elevated in the cerebrospinal fluid (CSF) of patients with HIVD. We also examined the possibility that such MMPs could be produced by brain-derived cells, and that MMP production by these cells might be increased by tumor necrosis factor-alpha, an inflammatory cytokine that is produced by HIV-infected monocytes/microglia and is elevated in HIVD. By using western blot and enzyme-linked immunosorbent assay, we observed that CSF levels of pro-MMP-2 and pro-MMP-7 were increased in association with HIVD. In addition, through the use of gelatin substrate zymography, a sensitive functional assay for MMP-2 and MMP-9, we observed that MMP-2 or pro-MMP-9 activity was more frequently detectable in the CSF of individuals with HIV dementia (9/16) than in the CSF from either nondemented seropositive (2/11) or seronegative (0/11) controls. Although the presence of MMPs in the serum could contribute to elevated levels in the CSF, we also show that brain-derived cells release MMP-2, 7, and 9, and that such release is increased after their stimulation with tumor necrosis factor-alpha. Together, these results suggest that elevated CSF levels of select MMPs may reflect immune activation within the central nervous system. They also suggest that further studies may be warranted to determine whether these proteins may play a role in the development of symptomatic neurological disease.
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PMID:Cerebrospinal fluid levels of MMP-2, 7, and 9 are elevated in association with human immunodeficiency virus dementia. 1048 70

Infection of the brain by lentiviruses, including human immunodeficiency virus (HIV) and feline immunodeficiency virus (FIV), causes inflammation and results in neurodegeneration. Molecular diversity within the lentivirus envelope gene has been implicated in the regulation of cell tropism and the host response to infection. Here, we examine the hypothesis that envelope sequence diversity modulates the expression of host molecules implicated in lentivirus-induced brain disease, including matrix metalloproteinases (MMP) and related transcription factors. Infection of primary macrophages by chimeric HIV clones containing brain-derived envelope fragments from patients with HIV-associated dementia (HAD) or nondemented AIDS patients (HIV-ND) showed that MMP-2 and -9 levels in conditioned media were significantly higher for the HAD clones. Similarly, STAT-1 and JAK-1 levels were higher in macrophages infected by HAD clones. Infections of primary feline macrophages by the neurovirulent FIV strain (V(1)CSF), the less neurovirulent strain (Petaluma), and a chimera containing the V(1)CSF envelope in a Petaluma background (FIV-Ch) revealed that MMP-2 and -9 levels were significantly higher in conditioned media from V(1)CSF- and FIV-Ch-infected macrophages, which was associated with increased intracellular STAT-1 and JAK-1 levels. The STAT-1 inhibitor fludarabine significantly reduced MMP-2 expression, but not MMP-9 expression, in FIV-infected macrophages. Analysis of MMP mRNA and protein levels in brain samples from HIV-infected persons or FIV-infected cats showed that MMP-2 and -9 levels were significantly increased in lentivirus-infected brains compared to those of uninfected controls. Elevated MMP expression was accompanied by significant increases in STAT-1 and JAK-1 mRNA and protein levels in the same brain samples. The present findings indicate that two lentiviruses, HIV and FIV, have common mechanisms of MMP-2 and -9 induction, which is modulated in part by envelope sequence diversity and the STAT-1/JAK-1 signaling pathway.
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PMID:Lentivirus infection in the brain induces matrix metalloproteinase expression: role of envelope diversity. 1090 75

The pathogenesis of human immunodeficiency virus type 1 (HIV-1)-associated dementia (HAD) is mediated mainly by mononuclear phagocyte (MP) secretory products and their interactions with neural cells. Viral infection and MP immune activation may affect leukocyte entry into the brain. One factor that influences central nervous system (CNS) monocyte migration is matrix metalloproteinases (MMPs). In the CNS, MMPs are synthesized by resident glial cells and affect the integrity of the neuropil extracellular matrix (ECM). To ascertain how MMPs influence HAD pathogenesis, we studied their secretion following MP differentiation, viral infection, and cellular activation. HIV-1-infected and/or immune-activated monocyte-derived macrophages (MDM) and human fetal microglia were examined for production of MMP-1, -2, -3, and -9. MMP expression increased significantly with MP differentiation. Microglia secreted high levels of MMPs de novo that were further elevated following CD40 ligand-mediated cell activation. Surprisingly, HIV-1 infection of MDM led to the down-regulation of MMP-9. In encephalitic brain tissue, MMPs were expressed within perivascular and parenchymal MP, multinucleated giant cells, and microglial nodules. These data suggest that MMP production in MP is dependent on cell type, differentiation, activation, and/or viral infection. Regulation of MMP expression by these factors may contribute to neuropil ECM degradation and leukocyte migration during HAD.
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PMID:Mononuclear phagocyte differentiation, activation, and viral infection regulate matrix metalloproteinase expression: implications for human immunodeficiency virus type 1-associated dementia. 1141 25

The release of neurotoxins by activated brain macrophages or microglia is one mechanism proposed to contribute to the development of neurological disease following infection by lentiviruses, including feline immunodeficiency virus (FIV). Since molecular diversity in the lentiviral envelope gene influences the expression of host molecules implicated in neuronal injury, the role of the envelope sequence in FIV neuropathogenesis was investigated by using the neurovirulent FIV strain V1CSF, the nonneurovirulent strain Petaluma, and a chimera (FIVCh) containing the V1CSF envelope gene in a Petaluma background. All three viruses replicated in primary feline macrophages with equal efficiency, but conditioned medium from V1CSF- or FIVCh-infected cells was significantly more neurotoxic than medium from Petaluma-infected cultures (P < 0.001) and could be attenuated in a dose-dependent manner by treatment with either the matrix metalloproteinase (MMP) inhibitor prinomastat (PMT) or function-blocking antibodies to MMP-2. Although FIV sequences were detectable by PCR in brain tissue from neonatal cats infected with each of the viral strains, immunohistochemistry revealed increased astrogliosis and macrophage activation in the brains of V1CSF- and FIVCh-infected cats relative to the other groups, together with elevated markers of neuronal stress that included morphological changes and increased c-fos immunoreactivity. Similarly, MMP-2, but not MMP-9, mRNA and protein expression was increased in brain tissues of V1CSF- and FIVCh-infected cats relative to Petaluma-infected animals (P < 0.01). Infection with V1CSF or FIVCh was also associated with greater CD4(+) cell depletion (P < 0.001) and neurodevelopmental delays (P < 0.005), than in Petaluma-infected animals; these deficits improved following PMT therapy. These findings indicated that diversity in the envelope gene sequence influenced the neurovirulence exhibited by FIV both in vitro and in vivo, possibly through a mechanism involving the differential induction of MMP-2.
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PMID:Envelope gene-mediated neurovirulence in feline immunodeficiency virus infection: induction of matrix metalloproteinases and neuronal injury. 1186 28

Chemotactic cytokines or chemokines form a family of proinflammatory proteins that are functionally linked to various classes of proteases, including matrix metalloproteinases (MMPs). Both families of molecules are key players in the migration of inflammatory cells in autoimmune diseases and in invasive cancers. For example, the chemokine interleukin-8 acts as a fast secretagogue of gelatinase B in granulocytes and is increased in the synovial fluid of arthritis patients and may locally recruit and activate neutrophils. The latter are the most abundant inflammatory cell type in the joints of patients with rheumatoid arthritis. In the case of the inflamed joint, the contribution of matrix remodeling enzymes in the breakdown of cartilage and bone is trivial. Gelatinase B (MMP-9) was documented in autoimmune diseases and cancer by immunohistochemistry with the use of monoclonal antibodies. Studies in rheumatoid arthritis and multiple sclerosis led us to postulate the "Remnant Epitopes Generate Autoimmunity" or REGA model for autoimmunity. This model is based on the pathophysiological role of three major classes of molecules involved in aspecific primary immune defense mechanisms: the cytokines, the chemokines and the proteases. The REGA model has proven to be useful for the development of disease treatment strategies. Particular cytokines are disease-limiting and may thus be used for the treatment of autoimmune disorders. Cytokines and chemokines that induce enzymes promote disease and may be antagonized. Along this line of research, we have recently identified natural and biosynthetic chemokine antagonists. Some of these have shown potent antiviral activity against human immunodeficiency virus. It is expected that these might also become useful in the treatment of autoimmune diseases and invasive cancers. A similar effect may be expected by the antagonization of damaging proteases or with the use of recombinant or synthetic enzyme inhibitors.
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PMID:Chemokines and proteinases in autoimmune diseases and cancer. 1208 66

Cell invasion and angiogenesis are crucial processes in cancer metastasis that require extracellular matrix (ECM) degradation. Proteolytic degradation of the ECM components is a central event of invasion and angiogenesis processes. During these processes, matrix metalloproteinases (MMPs) seem to be primarily responsible for much of the ECM degradation. Disulfiram is frequently used in the treatment of alcoholism and has been reported to possess antiretroviral activity and can eject intrinsic zinc out of human immunodeficiency virus (HIV) nucleocapsid protein. In this report, we show that disulfiram inhibited invasion and angiogenesis in both tumor and endothelial cells at nontoxic concentrations. The 3H-labeled type IV collagen degradation assay suggested that disulfiram has type IV collagenase inhibitory activity, and this inhibition was responsible for blocking invasion and angiogenesis through cell-mediated and non-cell-mediated pathways. However, the mechanisms underlying cell-mediated signal pathways are not fully characterized. Our data demonstrate that the non-cell-mediated pathway is dominant. Thus, disulfiram could directly interact with MMP-2 and MMP-9 and inhibit their proteolytic activity through a zincchelating mechanism. Addition of zinc could reverse the inhibition of invasiveness and collagenase inhibition through disulfiram treatment. This finding implies that MMP-2 and MMP-9 may be the inhibitory targets for a potential disulfiram treatment. These observations raise the possibility clinical therapeutic applications for disulfiram used as a potential inhibitor of metastatic cell invasion and angiogenesis.
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PMID:Inhibition of invasion and angiogenesis by zinc-chelating agent disulfiram. 1457 56

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